CLINICAL AND MORPHOLOGICAL CHARACTERIZATION OF FETOPLACENTAL COMPLEX IN PREGNANT PATIENTS WITH DIFFUSE TOXIC GOITER

Background: The course of pregnancy and delivery in patients with diffuse toxic goiter (DTG) is often complicated by preeclampsia, fetoplacental insufficiency, placental abruption and associated with higher maternal and perinatal mortality.

Aim: To study particulars of fetoplacental complex functioning in DTG.

Materials and methods: We assessed pregnant patients with DTG (n = 92) and their newborns (n = 94). By the time of delivery, 86 of patients were clinically and biochemically euthyroid. Functions of fetoplacental complex (by levels of placental lactogen, α-fetoprotein, estriol, progesterone and cortisol) were assessed by radioimmune and immunoenzyme assays. Fetometrical parameters of fetuses were studied by ultrasound method. Complex assessment of placentas was done by light and electronic microscopy.

Results: Eighty seven (94,6%) patients with DTG had combined complications of pregnancy. The most frequent were: the threat of termination of pregnancy, in 68 (73.9%) of cases, low placenta placement, in 23 (25%), anemia, in 56 (60.9%), pre-eclampsia, in 56 (60.9%). In 59 of patients (64.1%), fetoplacental insufficiency was diagnosed, with predominance of strain or exhaustion reactions. Critical status of fetoplacental complex was found in pregnant patients with uncontrolled DTG and duration of control of less than 20 weeks, as well as in pregnant patients with DTG relapses. The values of main hormones (placental lactogen, α-fetoprotein and progesterone) were below 10th percentile.

According to the results of the ultrasound assessments, fetuses from mothers with DTG during gestation demonstrated decrease of the majority or percentile parameters, such as biparietal cranial size, fetal femoral length, abdomen diameter, that was especially prominent in the groups with relapsing DTG.

Eighty eight of 94 newborns (93.6%) were born full-term. In total, every third baby (29.3%) had some degree of intrauterine developmental delay at birth. Among the cases with controlled DTG in mothers, there were 21.2% of such babies, whereas among those with DTG relapses, 40%. There was an association between the length of DTG control during pregnancy and mass and body parameters of newborns: the shorter was duration of DTG control during gestation, the higher was the risk of low birth weight fetuses (р < 0.05).

Histological assessment of placentas from DTG patients showed changes of endothelial microlandscape with sprouting of cell plasmolemma, blood cell adhesion and fibrin deposition. In 86% of placentas there were stasis, sludge formation and thrombosis in cord vessels.

Conclusion: Pregnancy starting during uncontrolled DTG is typically associated with primary placental insufficiency that is morphologically characterized by profound metabolic abnormalities (stromal fibrosis, immaturity of the villous tree, blood flow abnormalities and ischemia). Morphological and functional placental abnormalities correlated with duration of uncontrolled DTG and lead to high rate of intrauterine developmental delay.